Changes

On the top, 32K RAM (contents are held by lithium battery so can survive a reset or power off), which can be programmed like ROM and occupies two ROM positions (1 and 2 I think).Also and also sockets for more expansion ROMs up to max ROM 7.

Also there There is a bank of DIP switches to enable/disable ROM slots, a switch to enable/disable writes to 32K RAM(left side of top pcb), a LED to indicate RAM is ready to write and a switch to reset computer(right side of top pcb).

It seems the first few batches of these were distributed without boxes, so you had to provide your own, because the box I have with mine is home made.